Collapsible tube



June 3, 1941- P. R. FECHHEIMER COLLAPS IBLE TUBE Original Filed Feb. 12,1954 INVENTOR. B401. R i'EcHHE/MER.

, ATTORNEYS.

Patented June 3, 1941 ,STATE S DFFIC COLLAPSEBLE TUBE.

Paul It. Fechheimer, Cincinnati, Ohio,assignor'to TheKarl Kiefer MachineCompany,

Cincinnati,

Ohio, a corporation of Ohio 3 Claims.

the tube so that its bottom edges are contiguous and lie in parallelplanes, and then to fold these edges over upon themselves a plurality oftimes, afterward frequently holding the fold together by means of a clipof stiffer metal fastened thereto,

orby lockingthis'fold by means of a crimp or fold- 1 ing back of thecorners. These methods of sealing, while effective for most purposes,are sometimes uneconomical because they involve added cost, but moreimportantly, they do not provide a hermetic seal for the bottom of thetube. This becomes of importance, for example, where tubes containingliquefiable paste are shipped into warm or torridclimates, or are storedunder elevated temperatures, Where the contents of the tube becomeliquefied, or where for any reason a pressure is built up inside thetube, the contents are frequently forced outwardly through the bottomclosure and serve to stain and destroy the appear- .ance andserviceability of the tube itself, and of the wrapplngs or package inwhich it is contained.

It therefore appears as another object of my invention, toprovidecollapsible tubes sealed so as to provide a liquid and gas tightjoint in the nature of a hermetic seal.

These and other objectsof my invention, which will be set forthhereinafter, or will be apparent to one skilled in the art upon readingthese specifications, I accomplish by that series of process steps andby and in the constructions which I hereinafter disclose in exemplaryembodiments.

Reference is made to the drawing, wherein Figure l is a sectional Viewof a sealing means.

Figure 2 shows the bottom end of a tube sealed by welding, and the beadformed thereby.

Figure 3 is a view showing such a welded tube with its bottom folded ina simple fold.

It will be understood that after the filling of a collapsible tube,which is usually done through the open bottom thereof, while the tube isin an inverted position, the bottom edges of the tube are spread so asto form a fish tail, and so as to bring these bottom edges togetherflatwise, so that they lie in parallel planes. They are then held inthis position by clamp members engaging the side Walls of the tube-fromeither side. The welding together of the juxtaposed bottom edges of thetube presents in practice, some serious problems. The metal of the tubeedges is very thin and quite likely to burn through. Thus, if heat wereapplied to the clamping members engaging the juxtaposed bottom edges,while a weld might be effected therebetween the tube walls have atendency to burn-through at the edges of the heated members. I-havefound, however, that it is possible to do commercially successful andreliable Welding by the procedure hereinafter to be outlined in detail.This procedure involves in the main, the clamping of the edges of thebottom of the tube so as to hold these edges in juxtapositionedrelationship, but in such a way as to leave these edges projecting ashort distance beyond the clamping means. If this isdone and if theclamping means themselves are not relied upon to do the welding,successful welding can be carried on at the end of thetube in thatportion thereof which projects freely above the clamping devices. I havefound moreover, that it is preferable to carry on this welding in acontinuous and progressive manner by starting with a tool at one end ofthe juxtaposed edges and progressively forming a Weld therealong,finally reaching the other end of the juxtaposed edges, In other words,it is preferable, although not a limitation upon the broader aspects ofmy invention, to carry on the welding with a tool which has, practicallyspeaking, a point contact with the work, and by moving the work and thetool relatively to each other during the progress of the weldingoperation.

I have described in Patent 2,102,840, an exemplary filling and closingmachine which happens to be of the continuous motion type. My inventionis not, however, limited to this type, but is clearly applicable tomachines having a step by step motion, or to filling and closingoperations which are carried on as separate steps or disher 4a. Theholder 41) is hollowed out as at T and 8, to accept the top of acollapsible tube when the tube is in inserted position, and the holdermay likewise be provided with a kick-out device comprising a plunger 9,and a spring 10, serving to hold the plunger in depressed position. Thebase member 4a has ears thereon 40, which engage the track members H onthe base i.

The holder member 41) has a projection (not shown) at its side, to whichis attached a vertical rod, also not shown. This rod bears at its upperend a pair of clamping jaws l3 and I4, hinged thereto, and urged to anoutward position by a spring.

. Empty collapsible tubes may be inserted into the holders, and thetubes are then conveyed to a filling device to be filled as will bereadily understood without further description. When so filled they passfrom beneath the filling spouts and are acted upon by some device whichspreads or fishtails the bottom end of the tube so that the edges canlater be brought into juxtaposition by the action of the clamp membersl3 and [4.

During the further course of the progress of the tube, track members 23and 24 engage the clamp members i3 and i4 and bring them together aboutthe fishtailed tube end. In this way the tube edges are brought to lieagainst each other in parallel fiat planes. In Figure 1 it will be seenhow the clamping members I3 and I4, held together by the track members23 and 24, engage the end of the tube, and it will also be seen how afree portion of the tube ends projects above the clamping members [3 andM, as at C.

The tube so disposed and held is caused to pass beneath a welding deviceof cylindrical form, indicated at 25. This member is held above asuitable bracket 2'6. It is grooved as at 27 in that portion of itssurface which is to contact the juxtaposed edges of the tube bottom. Itis convenient to make the groove 27 an annular groove extendingcircumferentially about the surface of the welding member 25. If anyportion of this groove becomes fouled or otherwise unsuitable, itwillthus be possible to rotate the welding member slightly in the bracket26, so as to present to the tube edges afresh portion of the groove. Thewelding member 25 may comprise an outer casing 25a, and an interiorlydisposed electric heating coil (not shown), having means for anelectrical J connection indicated broadly at 29.

It is convenient and economical to use electrically heated members, butmembers otherwise heated may be used as well as, in some instances,means for generating electric heat in the tube walls, or means forapplying a flame thereto. In the claims which follow, the term weldingis to be understood as including any means for causing interfusion ofthe top walls of the tube.

It will be noted that the device of Figure 1 illustrates a preferredmethod of operation in which the welding is carried on in a progressivemanner from one end of the tube bottom edges to the other end. I havefound that more positive results can be secured more easily in this way.Figure 2 indicates that the welding operation preferably results in theproduction of a slight bead of consolidated metal indicated at 3|. InFigure 3 I have shown at 32 a simple fold produced in the metal of thetube end. This is by no means as complicated a fold as is ordinarilymade, nor does it take as much length of tube. The bead in. part servesto stiffen the bottom of the tube, but the fold is advisable for furtherstiffening, and also to take up the lengths of the tube which extendbetween the clamping members l3 and I4, and the place where the weldingis accomplished.

It will be understood that the embodiments of my invention which I havehereinabove described are exemplary only and that modifications may bemade in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. A collapsible tube having a flattened bottom portion presentingjuxtaposed edges of the tube Wall, and a line of Welding joining saidjuxtaposed bottom edges, said line of welding comprising an accumulationof the metallic substance of the wall edges themselves providing a bead.

2. A collapsible tube having a flattened bottom portion presentingjuxtaposed edges of the tube wall, and a line of Welding joining saidjuxtaposed bottom edges, said line of welding comprising an accumulationof the metallic substance of the wall edges themselves providing a beadof substantially greater thickness than said juxtaposed edges of thetube wall and having the characteristics of a bead formed by surfacetension in molten metal, the bottom edge portions of said tube beingfolded over upon themselves to form an additional stifiening structure.

3. A collapsible tube or like container having thin walls in which for aseal juxtaposed edges of said thin walls are welded together byinterfusion of the metal thereof, the weld comprising a head ofsubstantially greater thickness than said juxtaposed walls and havingthe characteristics of a bead formed by surface tension in molten metal.

